A database called an FCMDB (FCMDB: Federated Configuration Management Database) is known. This database is a database which virtually unifies databases of a plurality of types which manage information related to hardware and software constituting an information system to manage information of a resource constituting the system.
As shown in FIG. 1, the FCMDB is a virtually unified DB which makes it possible to cross-sectionally operate a plurality of databases, for example, a constituent information DB, an incident information DB, a trouble information DB, a release information DB, a change information DB, and an application information DB. Each of the plurality of unified databases manages a CI (Configuration Item) serving as attribute information related to a device (resource) constituting the system and a relationship between the pieces of information.
The FCMDB has a reconciliation function. This, as shown in FIG. 2, is to reconcile information by managing information of the same item managed by different names and different local IDs in units of databases by a unique ID (to be referred to as a global ID hereinafter) which can be commonly used in all the databases to reconcile the information.
In order to realize the reconciliation, pieces of information which are uniquely held and managed by each of the databases are associated with each other. In this association, as shown in FIG. 3, a global ID is given to each resource in advance, and the global IDs are matched with each other to identify the resource.
However, there are various pieces of operation management software, and not all databases always hold global IDs. As shown in FIG. 4, switch1 serving as an ID is included in a DB-A which is a database but is not included in a DB-B which is another database, and the mapping cannot be performed. In order to unify databases without contradiction or overlapping, it is required to make it possible to also identify an ID-deficit resource.